ESD Glossary

The transmission of a rogue electrical signal, caused by ESD, and received by a computer or electrical device and has the potential to cause disruption and downtime. An example of EMI is the static interference you may hear over an automobile radio, caused by lightning, when you drive in the vicinity of an electrical storm.

iPod/earbud Static Shocks

Recent static shocks caused by inserting charged earbuds into a person’s ear have prompted Apple Support to post a warning (Article: TS2729). There have apparently been numerous complaints about people getting shocks while listening to their ipod or iphone.

At first glance, it might seem that Apple’s equipment is the culprit−this writer believes that is highly unlikely. Here’s why:

How to avoid this issue:

Blow on your hands like a baseball pitcher does in the cold weather to create condensation in your palm.

Immediately take the earbuds and press them against your damp palm and hold them for a couple of seconds.

Prepare a pouch for your ipod before walking/running with it in your pocket

Take a small cloth pouch or piece of cotton [a sock] and rub it with an anti static fabric softener like Cling Free or Bounce. (The fabric softener will prevent the cloth from creating static in the first place.)

Place the ipod is in the pouch--the anti static coating on the pouch will prevent the charge from developing.

The device and earbuds should now be discharged.

Why does this happen?

Let’s start by thinking about the sources of static electricity. Static charges result whenever two surfaces rub together, then separate. We have all played with balloons and observed how much static can result from rubbing the balloon against human hair. In the case of an iphone or an ipod, the two surfaces are usually the electronic gadget or ipod and the lining of a pocket. If the pocket lining is a good static generator--any clothing material other than cotton--a static charge will probably build up on the device if it is shaken and rubbed inside the pocket.

Static charging is not really the problem.

Static discharging is the problem.

The easiest way to discharge a small device like an ipod or an iphone is to connect the device to a larger object with a wire.

(That is exactly what happens when an earbud cable is connected into the device and inserted into a human ear.) The charge on the device is invited to move from the device through the wire inside the earbud, then, on into the new point of contact – the ear--resulting in a minor zap. Since the ear is a particularly sensitive part of the body, a minor discharge feels more significant than it really is.

So, how can we avoid this problem?

Apple suggests wearing different clothing, handling the device less often and avoiding usage when it is dry. These don’t seem like realistic solutions to me. Should I carry around a humidifier to determine when it is safe to take phone calls on my cell?

I recommend discharging the earbuds before they ever make contact with your ear.

Blow on your hands like a baseball pitcher does in the cold weather to create condensation in your palm.

Immediately take the earbuds and press them against your damp palm and hold them for a couple of seconds.

The device and earbuds should now be discharged.

What if the device charges up while you are moving / using it?

This problem is a tricky because the source of the problem is your clothing – not the device. In all likelihood, you will probably be using clothing of some kind while using your iphone or ipod.

The best solution for this scenario is to:

Take a small cloth pouch or piece of cotton [a sock] and rub it with an anti static fabric softener like Cling Free or Bounce. (The fabric softener will prevent the cloth from creating static in the first place.)

Place the ipod in the pouch--the anti static coating on the pouch will prevent the charge from developing.

Why does it seem like Apple’s devices are the only ones that have this problem?

For a real accurate answer you’ll have to wait for the statisticians to create a probability model. However, the simple answer is that Apple probably has a 10 to 1 market share in the earbud/portable device market. Add the number of active people wearing ipods while they perform a moving activity and you probably have your answer. It’s all in the numbers of users and Apple certainly has them. Even if the chance of getting a shock is less than 1%, the number will still be high when you consider the millions of joggers and commuters wearing ipods and iphones.